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Lecture 3. Environmental Systems: Chemistry, Energy, and Ecosystems. What will I learn today?. Learn why chemistry is important in environmental biology See chemistry applied to real-world situations Learn the building blocks of living organisms
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Lecture 3 Environmental Systems: Chemistry, Energy, and Ecosystems
What will I learn today? • Learn why chemistry is important in environmental biology • See chemistry applied to real-world situations • Learn the building blocks of living organisms • Understand the types of energy and the basis energy flow in the Universe • Distinguish the different ways of making and using energy. • Learn about the origin of life on Earth • What do we understand about early life
Application of chemistry and biology to real world issues • Two great case studies…
Exxon Valdez Case study 1
Disaster • On March 24, 1989 • Alaska’s Prince William Sound • Tanker Exxon Valdez struck a reef • Spilled 42 million L (11 million gal) of crude oil • This oil eventually coated 2,100 km (1,300 mi) of Alaskan coastline. • The largest oil spill in U.S. history • it killed an estimated • 100,000-400,000 seabirds, • 2,600-5,500 sea otters, • 200-300 harbor seals, and countless fish.
Wild life was dying - The feathers of birds do not insulate when covered in oil. The birds were dying of hypothermia
Clean up effort - classical • The cleanup crews corralled the oil with • booms • skimmed it from the water • soaked it up with absorbent materials • and dispersed it with chemicals. • They pressure-washed the beaches, removed contaminated sand with backhoes and tractors, • and even tried burning the oil. • It simply was too slow or not working
Clean up effort - Biological • Scientists tested a new cleanup strategy • One that enlisted nature to help take care of the mess. • They stimulated naturally occurring bacteria to biodegrade, or break down, the oil. • About 5% of the natural bacteria present on Alaskan beaches feed on chemical compounds called hydrocarbons that are produced by conifer trees. • Hydrocarbons from conifers are chemically similar to the hydrocarbons that make up crude oil, so scientists predicted that the microbes might also be able to degrade oil. • Scientists from the EPA and Exxon decided to put the bacteria to work in a process called bioremediation • DEF - the attempt to clean up pollution by enhancing natural processes of biodegradation by living organisms.
Bioremediation • It worked on the test beaches • It was applied to all the areas suitable • Some say it helped… • Others say that it did little • In general it did aid in removing the oil • Now common for scientists and companies to offer a custom solution to a problem.
Dead Zone Case study 2
Gulf of Mexico • Each year in the spring and summer the ocean waters of the coast of Louisiana and troubled!!!
http://www.smm.org/deadzone/ • Watch this flash interactive lesson.
Bioremediation • Scientists have discovered that certain plants, bacteria, and animals have special systems that can be used • Consider…
Plants used as filters • When soil is contaminated with heavy metals from mining, manufacturing, or other causes, the standard solution has been to dig up tons of soil and pile it into a hazardous waste dump. • As an alternative, scientists are developing methods of phytoremediation, using plants to detoxify contaminated soils.
Toxic Selenium • Most heavy metals are toxic to plants, just as they are to wildlife and people. • But some plants can take up toxic elements and store them without harm. • The researchers concluded that the reed was most effective at removing selenium.
Chemistry • Atoms and elements are chemical building blocks • Lets see how much we know?
Each Group Take a minute and come up with a skit about how an atom is organized
Each Group Take a minute and come up with a skit explaining what an isotope is.
Atoms bond to form molecules and compounds • Take a minute and come up with a skit explaining the difference between molecules and compounds
The chemical structure of the water molecule facilitates life • Take a minute and come up with a list of features of water that make it very different from other compounds
Water • Hydrogen bonding • Freezing point • Boiling point • Density • Specific heat capacity
pH • Take a moment and come up with a good definition of what the pH scale measures and give good examples of each.
Matter is composed of organic and inorganic compounds • What is organic and what is inorganic? • Carbon atoms (and hydrogen) = organic • Mix in some N, O, S, P • Inorganic molecules lack C-C bonds
Macromolecules are building blocks of life • What is a macromolecule? • Very long! • Proteins • Carbohydrates • DNA & RNA
We create synthetic polymers • Give examples of synthetic polymers? • What are some of the issues with these synthetic polymers?
Organisms use cells to compartmentalize macromolecules • Isolation • Protection
The Origin of Life How life originated is one of the most centrally important, and intensely debated, questions in modern science.
Early Earth was a very different place • Earth formed about 4.5 billion years ago • For several hundred million years Earth was hostile • UV light • Volcanic activity • Lava • Comets
Several hypotheses have been proposed to explain life’s origin • Three prominent theories follow… • Listen and see which one do you relate to most?
Primordial soup: The heterotrophic hypothesis • life originated from a ‘primordial soup’ of simple inorganic chemicals dissolved in the ocean’s surface waters or tidal shallows. • Lab experiments have provided evidence that such a process can work. • 1953 Miller and Urey made simple organic molecules in a test tube!
